1. Field of the Invention
The present invention relates to a bearing for a ceramic rotor in a thermal turbine engine or turbomachine and rotating at high rotational speed, with a spherical air-supported bearing which has a lubricating air film maintained between its outer bearing ring and inner bearing ring.
2. Discussion of the Prior Art
In more recent periods a transition has been made to equip with air-supported bearings those turbine engines or turbomachines which run within particularly high temperature ranges, and whose individual components are therefore constructed of ceramic components, particularly in the range of the high temperature zones, since the usual lubrication of bearings by means of oil is only possible up to a maximum bearing temperature range of within about 200.degree. to 300.degree. C., but not at temperatures of 500.degree. and above, as can be present at the bearing locations of the ceramic rotors for such machines. It is presently known that for the bearing support of the rotor shafts for such turbine engines there may be employed spherical bearings which are necessary due to the thermal changes encountered in the housing components during machine operation. In the utilization of spherical air-supported bearings for the described instances of application, there is now encountered the problem that, because of the different thermal expansion of metal housings and ceramic rotors of such turbomachines which operate within a high temperature range (the coefficients of thermal expansion of predetermined ceramics distinguishes from those of the usual housing metals by approximately the tenth power), during the course of operation there occurs an axial displacement between the shaft bearing location, on the one hand, and the housing bearing location, on the other hand. However, a displacement of that extent cannot be absorbed by the spherical air-supported bearings and, as a consequence, leads to the destruction thereof.